Though, considering how much motion goes in in the mouth, and all of the complicated choreography that needs to happen to avoid it, it's amazing that we don't end up biting our tongues more often. I wonder how often other animals bite their tongues - whether they're more or less prone to it than humans. I imagine it'd hurt a lot if you were a lion or a crocodile. Or an elephant either, for that matter.

EDIT: A reader writes:

I imagine that biting your tongue is much worse in mammals than in most animals. Chewing is a uniquely mammalian innovation in the vertebrates. Most animals just bite down, with their jaws only working in one plane, to cut through whatever they are eating. Mammalian jaws are a bit less powerful, but have more flexible joints to allow the jaw to move in multiple planes, allowing us to chew by shifting the jaw back and forth a bit. That's what puts us at such risk for biting our own tongues. So, Draak probably doesn't have to worry too much about as much.

Chewing was a major innovation for mammals, and an under-appreciated one compared to things like hair, live-birth and warm-bloodedness (endothermy). By being able to chew, we can get more energy out of food with less effort spent on digestion, without the need for crops or gizzards, or to swallow stones! Chewing drove the development of another important mammalian innovation: Differentiation of our teeth, which was, in turn, a major new "evolutionary space" for development that opened mammals up to the their present diversity. And, since the change to the jaw joints that allowed chewing are the mammalian trait that actually fossilizes, it is how paleontologists define mammals.

The other major terrestrial animals capable of true chewing, the insects, have also had some success with it. I don't know how often they bite their tongues.